The Pilgrim nuclear power plant in Plymouth has been shut down, while plant workers investigate why recirculation pumps turned off on Thursday, officials said this morning.

The plant was shut down manually, as per procedure, by its operators at 3:34 p.m Thursday after the pumps were tripped.

The pumps are used to adjust power levels in the plant, said Carol Wightman, a spokeswoman for Entergy, the plant owners.

“The plant is in a safe condition. There’s no threat to public safety,” she emphasized.

The plant will restart after after a thorough evaluation and any necessary repairs are done, plant officials said.